Mechanism for intermittent feeding of combustion liquids to a combustion chamber in propulsion apparatus



June 7, 1955 R. H. GODDARD 2,709,890

MECHANISM FOR INTERMITTENT FEEDING OF COMBUSTION LIQUIDS TO A COMBUSTIONCHAMBER IN PROPULSION APPARATUS Filed March 26, 1952 INVENTOR. ROBERT H.GODDARDDECD. ESTHER BY 0. GODDARD, sxccumx.

nited States Patent MECHANISM FOR INTERMITTENT FEEDING OF COMBUSTIONLIQUIDS TO A COMBUSTION CHAMBER 1W PROPULSION APPARATUS Robert H.Goddard, deceased, late of Annapolis, Md., by Esther C. Goddard,executrix, Worcester, Mass., assignor of one-half to The Daniel andFlorence Guggenheim Foundation, New York, N. Y., a corporation of NewYork Application March 26, 1952, Serial No. 278,712

1 Claim. (Cl. 6035.6)

This invention relates to propulsion apparatus of the type in which acombustion chamber continuously discharges its exhaust gases through ar-earwardly-open discharge nozzle. When such a combustion chamber isused in aircraft, limitations of weight make it obviously essential thatmaximum power be developed from the combustion liquids, such as gasolineand liquid oxygen.

This maximum power development depends quite largely on providing a veryintimate mixture or inter mingling of the combustion liquids. To theattainment of this desired result, means is herein provided forintermittent or pulsating feeding of each of the combustion liquids.

If the flow interruptions are extremely rapid, the general effect isthat of continuous flow, but each stream of liquid tends to break upinto many small drops which mix much more easily than when the liquidsare fed uniformly and thereby tend to form separate films or layers.

The invention further relates to arrangements and combinations of partswhich will be hereinafter described and more particularly pointed out inthe appended claim.

Preferred forms of the invention are shown in the drawing, in which Fig.l is a front elevation of mechanism for providing intermittent orpulsating liquid feed;

Fig. 2 is a partial sectional elevation of a modified construction;

Fig. 3 is a front elevation of a construction in which the pulsatingwaves are produced by turbine action;

Fig. 4 is an enlarged sectional view of one of the turbines shown inFig. 3;

Fig. 5 is a sectional view indicating the production of waves in theliquid stream by a vibrating reed; and

Fig. 6 is a sectional view showing the interruption of feed as producedby a rapidly rotating bladed rotor.

Referring to Fig. 1, the combustion chamber C is shown as provided withan open discharge nozzle N, both of any usual construction. Feed tubes10 and 11 are connected into the otherwise closed end of the combustionchamber, and the tube 10 may receive a liquid oxidizer, as oxygen,through a supply pipe 12, while the tube 11 similarly receives a liquidfuel, as gasoline, through a supply pipe 14.

At their outer ends, the tubes 10 and 11 are closed by bellows members15 and 16. A solenoid 17 may be associated with each bellows member 15or 16, and the solenoid current may be rapidly interrupted by a magneticrelay 18, which operates a make-and-break switch 19 of any usual type.With this construction, the combustion liquids will be fed underpressure through the pipes 12 and 14 to the tubes 10 and 11, and will berapidly interrupted or caused to pulsate by the alternate expansion andcontraction of the bellows members 15 and 16.

The flow of the liquids to the combustion chamber then also assumes aninterrupted or pulsating form which is found to substantially facilitatethe breaking-up of the liquid streams into many fine drops.

If the length and diameter of the tubes 10 and 11 are properly selected,standing waves may be produced in the tubes, and the pulsating effectmay thus be magnified.

In Fig. 2, the tube 20, corresponding to the tube 11 previouslydescribed, receives a combustion liquid under pressure through a supplypipe 21 and is provided with a piston 22 at its outer end. This pistonmay be intermittently pressed inward against a spring 24 by a rotatedcam or eccentric 25. The pulsations thus produced are similar in effectto those produced by the construction shown in Fig. 1.

In Fig. 3, a combustion chamber C2 is provided with a nozzle N2, both ofusual construction, and one combustion liquid, as oxygen, is supplied tothe chamber C2 through a supply pipe 30, turbine pump P and tube 31,while the other liquid, as gasoline, is supplied from a pipe 33 througha turbine pump P2 and tube 34.

The detailed construction of the turbine pump P2 is shown in Fig. 4, inwhich a volute casing 36 eccentrically encloses a stator 40 comprising aplurality of fixed vanes 41.

Liquid from the pipe 33 is supplied at the axis of a rotor 45,preferably provided with a series of long vanes 46 and interposed shortvanes 47. The vanes or partitions 41, 46 and 47 are of such thicknessand spacing that the moving vanes substantially but momentarily closethe passages between the stationary vanes 41.

Consequently, the pressure of the liquid fed through the pipe 34 to thecylinder C2 is alternately increased and decreased as the vanes 46 and47 pass the openings between the stationary vanes 41. if the rotor isrotated at a relatively high speed, the rate of pressure interruption orpulsation will be correspondingly high.

In Fig. 5, a vibrating reed 50 is mounted in a recessed portion 51 in asupply pipe 52. As liquid under pressure flows through this recess, asindicated by the arrows, the reed it will be set in vibration and willproduce correspondingly rapid variations in the flow of the liquid outof the recessed portion 51. An interrupted or pulsating flow is thusvery simply obtained and with no moving parts except the vibrating reed.

In Fig. 6, a similar result is obtained by rotatably mounting a rotor inan enlarged portion 61 of a supply pipe 62. The rotor is provided withblades 64 which have close clearance in the casing portion 61 and alsoin the adjacent part of the pipe 62.

As liquid under pressure flows through this device in the direction ofthe arrows, the rotor 60 will be rotated at a speed definitely relatedto the rate of travel of the liquid, and the blades 64- will produceirregularities or slight interruptions in the fiow, so that apulsating'effect is produced.

With each of the constructions herein shown and described, the mainpurpose of the invention is attained by providing an interrupted orpulsating flow of both liquids to the combustion chamber, at which theyarrive in the form of small drops or are otherwise broken up for moreeffective mixing.

Having thus described the invention and the advantages thereof, it willbe understood that the invention is not to be limited to the detailsherein disclosed, otherwise than as set forth in the claim, but what isclaimed is:

In combustion mechanism for propulsion apparatus, a combustion chamber,means to feed a liquid fuel under pressure to said combustion chamber,means to feed a liquid oxidizer under pressure to said combustionchamber, and separate and additional means to impress a pulsatingpressure variation on each of said liquids while under otherwise normaland continuous feeding pressure, said additional means comprising avolute casing, a bladed stator within said casing, a bladed rotor withinsaid stator, means to supply a liquid under pressure to the interior ofsaid rotor and means by which said rotor is rotated by said liquid, andthe thickness of the blades in said rotor and stator being substantiallyequal to the spaces between said blades, so that the periods of liquidflow and flow interruption are substantially equal and each of extremelybrief duration.

References Qited in the file of this patent UNITED STATES PATENTS966,124 Rigg Aug. 2, 1910 10 Goddard Apr. 2, 1946 Wells Dec. 7, 1948Goddard Mar. 29, 1949 Rosenthal Sept. 13, 1949 Goddard Aug. 8, 1950Goddard Aug 8, 1950

